摘要
根据已发表的几种植物的甜菜碱醛脱氢酶(BADH)基因的AA同源保守区设计了1对简并引物,通过RT PCR方法从小麦叶片中扩增出BADHcDNA的中间序列,共72 3bp ,编码2 4 0个氨基酸。Northern杂交表明,扬花期遭受轻度水分胁迫时,抗旱性较强(旱丰970 3)与抗旱性较弱(山农2 15 95 3)的2小麦品种叶片中BADH基因的表达没有明显差异;灌浆期中度水分胁迫时,其表达水平明显增加,且旱丰970 3的表达量略高于山农2 15 95 3;乳熟期较严重土壤水分胁迫条件下,抗旱性强的品种BADH的表达量明显高于抗旱性弱的品种。3个生育期中,BADH活性和甜菜碱含量的变化与BADH表达呈现相同的趋势,均是先增加后降低,旱丰970 3的BADH活性与甜菜碱含量均高于山农2 15 95 3。这可能是旱丰970 3对干旱胁迫具有较强抗性的主要原因之一。
Under environmental stress,higher plants usually accumulate large amount of betaine for osmoregulation and resistance to osmotic stress. In recent years, betaine accumulation, activities of enzymes involved in betaine synthesis have become the subject of extensive study. Betaine aldehyde dehydrogenase(BADH), a key enzyme for betaine synthesis, stands the essential position in the synthesis of betaine.Betaine accumulation and BADH activity in higher plants are induced by drought stress, but there is little information about the relationship between plant drought resistance, BADH gene expression and betaine content in plants. In this study, we cloned the middle sequence of BADH cDNA of wheat (Triticum aestivum L.) leaf by PCR in order to find out the expression of BADH gene in two winter wheat cultivars(drought-resistant cultivar Hanfeng 9703 and drought-sensitive cultivar Shannong 215953) under drought stress at different developmental stages, and the relationship between drought resistance, BADH gene expression and betaine accumulation in the leaves were investigated. The main results were as follows: Two primers were designed according to the published sequences of BADH cDNA of several other plants and middle sequence of BADH cDNA of wheat (Triticum aestivum L.) leaf which contains 723 bp and encodes 240 AA amplified by PCR(Fig.2); Northern blot showed that there were little differences in the level of BADH gene expression between two wheat cultivars at flowering stage under slight drought stress, moderate drought stress led to the higher expression of BADH gene at seed filling stage, and which was slightly higher in Hanfeng 9703 than in Shannong 215953, however, at milk ripening stage, severe drought stress resulted in the decline of BADH gene expression, but the expression in Hanfeng 9703 was obviously higher than that in Shannong 215953(Fig.3). The changing trend of BADH activity and betaine content at three developmental stages was the same as that of the BADH gene expression, which increased firstly and the
出处
《作物学报》
CAS
CSCD
北大核心
2005年第4期425-430,共6页
Acta Agronomica Sinica
基金
国家重点基础研究发展规划项目资助 (G19980 10 10 0 )
关键词
小麦
干旱胁迫
BADH
NORTHERN杂交
甜菜碱
Wheat
Drought stress
Betaine aldehyde dehydrogenase(BADH)
Northern blot
Glycine betaine
